• The Journal of Korean Physical Therapy
• /
• v.24 no.1
• /
• pp.1-6
• /
• 2012

Purpose: The grip strength is influenced by various factors, such as position of the upper extremity, characteristics of the hand, and general physical condition. In this study, we investigated whether abdominal muscle activity in combination with the abdominal drawing-in maneuver has any effect on the grip strength in healthy young adults. Methods: This study included 31 healthy subjects (16 males, 15 females). We used surface electromyography and pressure bio-feedback unit for this experiment. All Subjects were placed in a cock-lying position with comfort and the grip strength was measured. On the following day, the pressure bio-feedback unit was placed beneath their fifth lumbar vertebra, and the, grip strength was measured again. This time, the measurement was taken while drawing-in their abdomen below the navel gently and gradually, while maintaining a neutral pelvic position. Results: The grip strength was significantly increased when subjects performed the drawing-in maneuver than when they were comfortable (p<0.05). In addition, activations of the rectus abdominal muscles significantly increased (p<0.05). Conclusion: In the current study, we found that abdominal muscle activity, in combination with the abdominal drawing-in maneuver, affected the grip strength, positively. Therefore, we suggest that this result should be considered when evaluating the grip strength.

• Applied Microscopy
• /
• v.43 no.4
• /
• pp.155-163
• /
• 2013

Meta-kaolin (MK) and blast furnace slag (BS) were used as raw materials with NaOH and sodium silicate as alkali activators for making geo-polymers. The compressive strength with respect to the various pre-curing conditions was investigated. In order to improve the recycling rate of BS while still obtaining high compressive strength of the geo-polymers, it was necessary to provide additional CaO to the MK by adding BS. The specimens containing greater amounts of BS can be applied to fields that require high initial compressive strength. Alkali activator(s) are inevitably required to make geo-polymers useful. High temperature pre-curing plays an important role in improving compressive strength in geo-polymers at the early stage of curing. On the other hand, long-term curing produced little to no positive effects and may have even worsened the compressive strength of the geo-polymers because of micro-structural defects through volume expansion by high temperature pre-curing. Therefore, a pre-curing process at a medium range temperature of $50^{\circ}C$ is recommended because a continuous increase in compressive strength during the entire curing period as well as good compressive strength at the early stages can be obtained.

• Journal of Society of Occupational Therapy for the Aged and Dementia
• /
• v.12 no.2
• /
• pp.47-55
• /
• 2018

Objective : The purpose of this study is to consider the change of hand function according to the quality of sleep and to find out a correlation among the quality of sleep and hand function, and sleep disturbing factors. Method : 23 patients who were hospitalized more than 6 months from Nov. 2017 to Jan. 2018 were tested for the quality of sleep used by sleep quality scale, for the grip strength used by a dynamometer, and for the coordination used by BBT and 9-Hole Peg test. The collected data were analyzed to implement the paired t-test and Pearson correlation coefficient. Result : In the high grade group of sleep score, the quality of sleep & BBT, and the grip strength & BBT have correlated each other; and in the medium group, only the latter has shown a correlation. In both groups, the quality of sleep and the sleep pattern have showed significant high correlation. Conclusion : When the elderly in geriatric hospitals show qualitative differences, BBT and the combination of treatment for the improvement of grip strength can improve the quality of sleep. And the sleep pattern intervention is considered to be effective to improve the quality of sleep.

• Computers and Concrete
• /
• v.12 no.5
• /
• pp.651-668
• /
• 2013

Concrete structures need repairing due to various reasons such as deteriorative effects, overloading, poor quality of workmanship and design failures. Cement based repair mortars are the most widely used solutions for concrete repair applications. Various factors may affect the bond strength between concrete substrate and repair mortars. In this paper, the effects of polymer additives, strength of the concrete substrate, surface roughness, surface wetness and aging on the bond between concrete substrate and repair mortar has been investigated. Full factorial experimental design is employed to investigate the main and interaction effects of these factors on the bond strength. Analysis of variance (ANOVA) under design of experiments (DOE) in Minitab 14 Statistical Software is used for the analysis. Results showed that the interaction bond strength is higher when the application surface is wet and strength of the concrete substrate is comparatively high. According to the results obtained from the analysis, the most effective repair mortar additive in terms of bonding efficiency was styrene butadiene rubber (SBR) within the investigated polymers and test conditions. This bonding ability improvement can be attributed to the self-flowing ability, high flexural strength and comparatively low air content of SBR modified repair mortars. On the other hand, styrene acrylate rubber (SAR) modified mortars was found incompatible with the concrete substrate.

• International Journal of Aerospace System Engineering
• /
• v.7 no.1
• /
• pp.16-20
• /
• 2020

The recent trend is increasing towards the usage of polymer matrix composites since they have a wide variety of applications. They have applications in the field of aircraft and space industry, sporting goods, medical devices, marine and automotive applications and also in commercial usage. The most commonly used fibre-reinforced polymer matrix composite is Glass fibre reinforced epoxy (GFRE) composite which is used in aviation, sports and automotive industries. However, the strength of GFRE composites is not adequate for structural applications. Therefore, the current research focuses on increasing the strength of GFRE composites by reinforcing with micro Graphite (Gr) particulates. The Gr used is an ultra-fine powder with particle size 250 ㎛. Gr is known to have good wear resistance, thermal conductivity and can operate at high temperatures. Gr particulates are mixed with the epoxy matrix in various weight ratios. Hand-lay technique is used for fabricating the composites. Mechanical properties such as tensile strength, elongation, compressive strength and flexural strength are obtained experimentally to study the effect of change in Gr content (0-5 wt. %). The tests were done as per ASTM standards.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.05a
• /
• pp.81-82
• /
• 2011

This paper is to compare and analyze WOE created by emulsifying waste oil & WOES added by stimulant with the existing SR in order to solve the problem of strength and reduction in fluidity occurring in time of the use of waste oil to reduce the autogenous shrinkage of high strength mortar. As experimental results, in case of WOE, there almost never happened a drop in fluidity at 1% replacement and compressive strength also showed the strength value similar to Plain. On the other hand, the effect of strength improvement consequent upon the use of stimulant was found to be insufficient. The change of autogenous shrinkage generally showed a better reduction effect in shrinkage comparing to Plain. In case of WOE1, reduction effect in autogenous shrinkage was found to be more excellent than the existing SR. Accordingly, WOE1 is analyzed to be desirable if reduction in autogenous shrinkage, strength & up to the aspect of fluidity are taken into consideration.

• PNF and Movement
• /
• v.18 no.1
• /
• pp.55-64
• /
• 2020

Purpose: The purpose of this study was to compare the strength and walking ability of chronic stroke patients following either proprioceptive neuromuscular facilitation (PNF) pattern training with pressure biofeedback units (feedback group) or PNF pattern training without pressure biofeedback units (control group). Methods: Eighteen participants with chronic stroke were recruited from a rehabilitation hospital. They were divided into two groups: a feedback group (n = 8) and a control group (n = 10). They all received 30 minutes of neurodevelopmental therapy and PNF training for 15 minutes five times a week for three weeks. Muscle strength and spatiotemporal gait parameters were measured. Muscle strength was measured by hand-held dynamometer; gait parameters were measured by the Biodex Gait trainer treadmill system. Results: After the training periods, the feedback group showed a significant improvement in hip abductor muscle strength, hip extensor muscle strength, step length of the unaffected limb, and step time of the affected limb (p<0.05). Conclusion: The results of this study showed that proprioceptive neuromuscular facilitation pattern training with pressure biofeedback units was more effective in improving hip muscle strength and walking ability than the proprioceptive neuromuscular facilitation pattern training without pressure biofeedback units. Therefore, to strengthen hip muscles and improve the walking ability of stroke patients, using pressure biofeedback units to improve trunk stability should be considered.

• Therapeutic Science for Rehabilitation
• /
• v.5 no.2
• /
• pp.23-33
• /
• 2016

Objectives: The aim of this study was to investigate the association between cognitive function and upper extremity function in the elderly. The articles were analyzed based on patient, intervention, comparison, and outcome using the P.I.C.O. principle. Methods: We systematically examined papers from January, 2000 to November, 2015 published papers through the foreign journals which were Medline & Pubmed for three months. mainly used key words were elderly, dementia, Alzheimer's disease, Mild cognitive impairment, age-related, aging, cognitive, upper extremity function, hand function, hand-grip strength, grip force, complex motor function, bimanual, dexterity, UE performance, and coordination. Results: The number of discovered outcomes for association between cognitive function and upper extremity function in the elderly was 7; grip strength & sex are impact on manipulation object, 1. The results show that cognitive function is associated with upper extremity function in the elderly. Conclusion: This study is expected to help selecting intervention, assessment tools according to the individual's degree of cognitive level and upper extremity function. In future domestic research, variety assessment tools need to be used and more qualitative level experiment will be carried out.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.8
• /
• pp.5364-5371
• /
• 2015

The purpose of the study is to prevent pain and malfunction of the hand by correcting the angle of holding a smartphone. Subjects comprised of 21 healthy students. This research was conducted from April 21 2014 to April 27 2014. The three groups were as follows: first group included 7 students who held the phone at an angle of 90 degrees without a sling, and second group included 7 students who held the smartphone at an angle of 90 degrees with a sling; and the third group included 7 students who held the smartphone at an angle of 120 degrees with a sling. VAS was measured through the Finkelstein Test. Also, pain rating and muscle strength were assessed four times 30 minutes before and after the experiment for one and a half hour with pinch grip, dynamometer, and visual analogue scale. Smartphone was used. In all of the measurements, period showed a significant difference (p<.05) between both sides and a significant difference was not found between the group. In the time ${\times}$ group, pain score and grip strength were significantly different in the right side only (p<.05). According to the results of this experiment, providing support to the hand helps to increase the hand function by reducing the stress.

• Journal of The Korean Society of Integrative Medicine
• /
• v.7 no.4
• /
• pp.33-41
• /
• 2019

Purpose : The muscle strength of iliopsoas (IL) was measured commonly in sitting position with hip and knee flexed 90°. However, there is no study to determine the muscle strength of IL in various test positions. Therefore, the purpose of this study was to compare the muscle strength of IL and muscle activity of rectus femoris (RF) according to test position and knee flexion angle. Methods : Twenty healthy subjects were participated for this study. The muscle strength of IL and muscle activity of RF were measured by hand-held dynamometer and surface electromyography during maximum voluntary isometric contraction (MVIC) of IL, respectively. The muscle strength of IL and muscle activity of RF was measured in 4 conditions as follows; 1) knee flexion angles 90 ° in supine, 2) 130 ° in supine position, 3) 90 ° in sitting, 4) 130 ° in sitting. Each condition were performed randomly by three repetitions. Results : The muscle strength of the IL was the main effect on the test position and knee flexion angle (p<.05), and the muscle activity of RF was the main effect only on the knee flexion angle (p<.05). There was also no interaction between the factors (p>.05). In supine position, the muscle strength of IL in knee flexion 130 ° was significantly less than that in knee flexion 90 ° (p<.0125). In knee flexion 90 °, the muscle strength of IL in supine position was significantly greater than that in sitting position (p<.0125). The muscle activity of RF in knee flexion 130 ° was significantly less than that in knee flexion 90 ° in supine and sitting positions (p<.0125). Conclusion : When the muscle strength of IL was measured in clinic and sports fields, the supine position with knee flexion 130 ° was recommended to prevent the muscle activation of RF and to maintain the trunk stability.